On Apr 20, 9:35*am, Ted Shoemaker wrote:
Hello,

I'm NOT a woodworking expert, even in my imagination.

At the place we rent, there is an old wood swing in the back yard. *To
the best I can tell, it has never been painted nor stained. *It is
some years old. *The wood is silvered and weathered, and a little
cracked and split.

What happens if I stain it? *Obviously I can't prevent the damage
that's already happened. *But will it slow future harm -- or is it too
late?

Any time you put some protection on wood, it should help it. However,
before you stain or seal with any type of deck sealer, you should
clean the wood. The discoloration is a mix of decaying wood and
dirt. TSP (available at Lowe's) and a stiff brush will wash it
clean. Or if you have a low power pressure washer, you can prep with
that as well as long as you are very careful not to fuzz up the wood.

With the wood cleaned, allow it a week or so to dry. Apply sealer as
per manufacturer's instructions.

Also, what's the difference in *color* between staining old wood and
staining new wood? *That is, if I build something else (yes, at a
rental) and use the same stain on it, how will the two pieces look
together?

Unless you use an opaque (this is like a light weight paint) stain/
sealer, the pieces will look very different. As wood dries out,
especially when left in direct sunlight, the cellulose cells shrink
and crowd closer together. This makes it harder for them to absorb
stains. Also, wood can discolor, streak, and check, etc., which will
affect the appearance of the wood under a stain.

Clean wood you probably know about.

Chances of matching an old wood structure and a new wood addition are
pretty slim unless you apply an opaque stain/sealer. With more solids
in the s/s, it acts more like paint so your have a much greater chance
of matching over a similar s/s with less solids. The solids will sit
on top of the wood and not only provide more protection than a clearer
finish, but the characteristics of the older wood won't be peeking
through in the background.

If it were me, I would clean it thoroughly, and put a couple of coats
of deck PAINT on it. Roll it on with a 4" roller, hit your corners
with a brush. You will be surprised how fast it will go.

Robert